1. Nanopowder Synthesis
Nanopowder Synthesis
for Solid Oxide Fuel
for Solid Oxide Fuel
Cells Anodes
Cells DO QUANG
Anodes
Anh Mai
Supervisors:
Prof. François Gitzhofer
Yan Shen (PhD)
July 5th 2012 CREPE – Faculté de génie- Université de Sherbrooke Internship Master 2 IC

2. CONTENTS
I. Laboratory Overview
III. Project & Objectives
V. SOFC Fundamentals
VII. Methodology
IX. Results & Discussions
XI. Conclusion & Future work
Anh Mai DO QUANG 2

3. I. LABORATORY OVERVIEW
 Centre de Recherche en Energie, Plasma et
Electrochimie (CREPE)
Mission : develop new materials by using plasma process
Director : François Gitzhofer , ing. PhD
Research themes :
• Development of materials for solid oxide fuel cell (SOFC);
• Synthesis of nanopowder;
• Synthesis of new catalysts based on nanoscale materials by using plasma
technology;
• Application in nano-structured and new compositions of coating deposition
to improve the performances of aircraft turbines and diesel engines;
• Biomedical application (synthesis of bio-materials for prosthetic bones).
Anh Mai DO QUANG 3

4. I. PROJECT & OBJECTIVES
 PROJECT
Solid Oxide Fuel Cells (SOFC) :
• Applications : auxiliary power units in vehicles to stationary
power generation with outputs from 100 W to 2 MW
• Advantages : clean device, high efficiency, flexibility in the
choice of fuel, internal gas reforming, no moving part…
• Project :
- Work on SOFC anode materials within the NSERC Solid Oxide
Fuel Cells Canada Strategic Research Network
- Synthesis of nanoscale material by using plasma technology
Anh Mai DO QUANG 4

5. I. PROJECT & OBJECTIVES
 OBJECTIVES
• SOFC anode material : Lanthane Doped Ceria – Lanthane
Doped with Strontium titanate – Yttria Stabilized Zirconia
• Nanopowder synthesis with a pure nanostructured phase of
La0.4Ce0.6O2
• Contribution to the anode coating deposition of a
suspension of :
– La0.4Sr0.6TiO3 and yttria-stabilized zirconia on a thin disk
– La0.4Ce0.6O2 - La0.4Sr0.6TiO3 - yttria-stabilized zirconia on a
thin disk
The coating must be porous, homogeneous and provide a
good boundary at the anode/electrolyte interface
Anh Mai DO QUANG 5

6. I. SOFC FUNDAMENTALS
 HOW DOES A SOLID OXIDE FUEL CELL WORK?
– 3 main components : Anode – Electrolyte – Cathode
– Cathode reaction : O2 + 4e- → 2O2-
– Anode reactions : H2 + O2- → H2O + 2e-
CO + O2- → CO2 + 2e-
– Reformer reaction : CxH2x+2 + xH2O → xCO + (X+2)H2
– Operating temperature : 600°C-1000 °C
Anh Mai DO QUANG 6

7. Internal Reformer Supported SOFC Operation Principle
e e
e e
e
Green – Bio – Regular e Oxygen
Diesel
H
+ Water
H
H e
O
HO
e
2 H2 + O2 = 2 H2O C
O e
CO + ½ O2 = CO2
O O
C e
O
Electrolyte
Water + CO2 Reformer Anode Cathode
600-700˚C

8. I. SOFC FUNDAMENTALS
 ANODE REQUIREMENTS
– Stable in a reducing environment
– Suitable porosity
– Thermal expansion coefficient (TEC) similar to the other
components
– Tolerance to sulfur (5000 ppm)
– Catalytic activity towards electro-oxidation of fuels
– High electronic conductivity
– Sufficient ionic conductivity
Anh Mai DO QUANG 8

9. I. METHODOLOGY
• Synthesis of LDC powder by
solution plasma spraying
Solution of La0.4Ce0.6O2 is made of
La(NO3)3•6H2O and Ce(NO3)3•6H2O
Plasma torch Tekna PL - 50
Torch nozzle diameter 45 mm
Central plasma gas (Ar) 27 slpm
Sheath plasma gases (O2) 80 slpm
Atomization gas (Ar) 11.4 slpm
Plasma power 35-40 kW
Chamber pressure 150 Torrs
Solution injection flow rate 5-4 ml/min
Anh Mai DO QUANG 9

10. Solution
Torch
Vacuum
Reactor Porous metal filter
Filter Unit

11. I. METHODOLOGY
• Deposition of La0.4Sr0.6TiO3 – Yttria Stabilized Zirconia
on a thin Yttria Stabilized Zirconia disk (~380 µm) by
suspension plasma spraying
– Solution of La0.4Sr0.6TiO3 + suspension of Yttria
Stabilized Zirconia nanopowder.
• The solution of La0.4Sr0.6TiO3 was made of a nitrate
solution of lanthanum and strontium which was
stirred with titanium propoxide and triethanolamine
– Several tests of the disks in the plasma with varied
parameters (spraying distance, power…)
Anh Mai DO QUANG 11

12. I. RESULTS & DISCUSSIONS
• Lanthanum Doped Ceria XRD : First Synthesis
Plasma power 35 kW
Solution concentration 1 mol/L
Solution injection flow rate 5 ml/min
Anh Mai DO QUANG 12

13. I. RESULTS & DISCUSSIONS
• Lanthanum Doped Ceria XRD : Second Synthesis
Plasma power 40 kW
Solution concentration 0,8 mol/L
Solution injection flow rate 4 ml/min
Anh Mai DO QUANG 13

14. I. RESULTS & DISCUSSIONS
• Lanthanum Doped Ceria TEM : Second Synthesis
Anh Mai DO QUANG 14

15. I. RESULTS & DISCUSSIONS
• Coating deposition of LST-YSZ on the thin
substrate
 Proper deposition way and suitable plasma
parameters of preventing the YSZ disks from cracking
have been finished
 The quality of the coating still needs to be improved
Anh Mai DO QUANG 15

16. CONCLUSION AND FUTURE
WORK
 CONCLUSION
 Lanthanum Doped Ceria powder synthesis : suitable parameters
have been found to obtain a pure phase
 Lanthanum doped Strontium Titanate – Yttria Stabilized Zirconia
deposition : suitable parameters for the survival of disk have been
found but not for the quality of the coating
 FUTURE WORK:
– Lanthanum Doped Ceria powder : Do the synthesis again
– Coating deposition of Lanthanum doped Strontium Titanate – Yttria
Stabilized Zirconia : overcome the thermal shock problem (micro-
heater), new substrate
– Do experiments for Lanthanum Doped Ceria – Lanthanum Doped
with Strontium titanate – Yttria Stabilized Zirconia
Anh Mai DO QUANG 16

17. ACKNOWLEDGEMENT
 SPECIAL THANKS TO :
o Prof. François Gitzhofer, for his general supervision and his
advice during the internship;
o Yan Shen, a PhD candidate, for following me up during this
internship;
o Kossi Béré, the lab technician, for his precious help during the
experiments;
o Mingwen Guo, a Master candidate, for his assistance ;
o Stéphane Gutierrez and Charles Bertrand for their work to the
sample characterization ;
o SOFC Canada for their funding support and for their invitation
to the SOFC annual general meeting at Calgary.
Anh Mai DO QUANG 17